The Supreme Court had Tuesday ordered the anti-corruption body to arrest the prime minister and 15 other people accused of taking kickbacks in power projects when Ashraf was the minister for water and power.

A three-member bench of the Supreme Court headed by Chief Justice Iftikhar Muhammad Chaudhary had ordered the National Accountability Bureau (NAB) to arrest the prime minister and submit a report by Thursday, Xinhua reported.

However, the NAB refused to arrest the prime minister on the plea that its own investigation report in the corruption case was flawed and that evidence was not enough to arrest him.

NAB chief Fasih Bukhari told the apex court that the bureau's inquiry report earlier submitted to the court was inaccurate.

He said investigation officers had worked in a hurry and did not provide proof in the report.

The chief justice said that the NAB needed to justify as to why the court's directives was not implemented.

"Why could there be no record against the accused and why had no arrests been made," the chief justice asked.

He said the implementation of the court's ruling had been in pending since March 2012 and that the NAB chief was also issued a notice for contempt of court.

Legal experts told Xinhua that despite the arrest order, the prime minister can continue his duties unless he is convicted.

The apex court in its earlier verdict in March last year had said that rules and regulations were violated in the power projects due to which the national exchequer witnessed losses of billions.

The court has now declared the projects illegal and also ordered them to be shut down.